Ok, I'm not a rigger, and not generally familiar with reading a TSO. What's different? I skimmed through, and the last part (5) seems to jump out at me. As I read it, it seems to imply that a reserve to be considered "safe" should be loaded light enough to get an incapacitated for whatever reason down pretty much injury free.

5. Page 11, disregard paragraph 4.3.9.1., Rate of Descent Tests (Method 2). We omitted the Method (2) testing, for not providing an equivalent level of safety to current standard. This method is directed at high performance and experience parachutists in sport and skydiving activities. Novice or less experienced parachutists in emergency conditions due to incapacitation, panic, etc., may not be able to safely deploy and land. We have to consider the safety of all jumpers, not just the highly skilled, highly experienced. It is argued that the risks the experienced jumpers are exposing themselves to, are mitigated by their skill and experience.

To allow the increased velocity may improve the safety of highly skilled, highly experienced jumpers, but it erodes the safety for the beginner, incapacitated, panicked, or a jumper who has gotten himself into a treacherous landing area. TSO-C23f 09/21/2012 Page 6 We do not agree that a canopy manufacturer can demonstrate that a jumper can safely land with an appropriate control manipulation while performing a flare before touchdown. This approach relies on jumper’s experience to meet the MOPS that parachutes have been certified to. This approach does not provide an equivalent level of safety.

Re: [skydived19006] TSO C-23f has been signed and issued
[In reply to]

Can't Post

All TSOs are basically 1 or 2 page letters which accept another organization's standards as the FAA's own. For C23b, the standard is NAS-804; for C23c, AS8015A; for C23d, AS8015B; for C23f, PIA TS-135.

The standard of TSO-C23d (AS8015B 4.3.7) required an average rate of descent not more than 24 fps, and total velocity (along the flight path) not more than 36 fps. The FAA wanted to keep that standard for C23f.

For both 23d and 23f, manufacturers can choose to TSO at any weight equal to or greater than 220 pounds/100kg. It's tough to design canopies that wingload at 2.2 (that's 220#/99 sq ft) and still meet the rate of descent and total velocity standards in the "unaltered post-deployment configuration," that is, with the brakes stowed. One solution is PIA TS-135 Test Method 2, which allows a jumper to flare the canopy to meet the rate of descent and total velocity maximums. The FAA doesn't like that Test Method 2 requires a jumper to be conscious and capable.

What the FAA is saying in TSO-C23f is that the PIA can include Method 2 in the PIA standards, but that portion of the PIA standards is not included in the FAA standards.

For both 23d and 23f, manufacturers can choose to TSO at any weight equal to or greater than 220 pounds/100kg. It's tough to design canopies that wingload at 2.2 (that's 220#/99 sq ft) and still meet the rate of descent and total velocity standards in the "unaltered post-deployment configuration," that is, with the brakes stowed. One solution is PIA TS-135 Test Method 2, which allows a jumper to flare the canopy to meet the rate of descent and total velocity maximums. The FAA doesn't like that Test Method 2 requires a jumper to be conscious and capable.

What the FAA is saying in TSO-C23f is that the PIA can include Method 2 in the PIA standards, but that portion of the PIA standards is not included in the FAA standards.

Mark

Thanks for the clarification Mark. Just a few thoughts.

I think that the current speeds are high enough. In fact I think that in many cases they are beyond survivable. 36fps is faster than the fastest men on earth can run.

I don't get the idea of test method 2. What are the folks at PIA trying to do?! Find a way to certify a 55 sq.ft reserve?

For both 23d and 23f, manufacturers can choose to TSO at any weight equal to or greater than 220 pounds/100kg. It's tough to design canopies that wingload at 2.2 (that's 220#/99 sq ft) and still meet the rate of descent and total velocity standards in the "unaltered post-deployment configuration," that is, with the brakes stowed. One solution is PIA TS-135 Test Method 2, which allows a jumper to flare the canopy to meet the rate of descent and total velocity maximums.

I don't get the idea of test method 2. What are the folks at PIA trying to do?! Find a way to certify a 55 sq.ft reserve? No. The goal is to get a reserve that can be jumped in the same wind conditions as the main. Your personal wind maximum may be lower, but there are plenty of skydivers who are comfortable jumping their highly loaded main canopies in winds of 25mph or more. A smaller reserve would be a better match for those conditions than a larger reserve. A serendipitous benefit would be a reserve that plays nicer with the main in the unlikely event of a two-out.

No. The goal is to get a reserve that can be jumped in the same wind conditions as the main. Your personal wind maximum may be lower, but there are plenty of skydivers who are comfortable jumping their highly loaded main canopies in winds of 25mph or more. A smaller reserve would be a better match for those conditions than a larger reserve. A serendipitous benefit would be a reserve that plays nicer with the main in the unlikely event of a two-out.

Mark

I would assert that the justification is to get a reserve that can be jumped in the same wind conditions as the main. I would venture that the goal is to get a reserve that packs in the same volume as the main for cosmetic reasons.

You mention jumping in winds in excess of 25 mph. If you need a wing loading of in excess of 2/1 to have a rigid wing in the conditions then these guys must be jumping in wind more in the range of 40 mph, I really doubt that's the case. At 1.5 or 1.6 with a wing that's loaded toward the front (not designed for light front riser pressures), you're going to be rigid in wind to 30 plus, depending on gusting. But then if it's gusting 10 to 35, you're not going to have much certainty in a descent landing on any wing under any loading in my opinion.

I can not see any hard surface landing at 2.2 done without pilot input being something that's not going to require a trip to the hospital.

Interesting none the less. What we ("we" as in not me) won't justify in order to look good.